vhost: fix sign extension in async packed ring
vhost: fix sign extension in async packed ring

Change the variable type in store_dma_desc_info_packed() to fix
suspicious implicit sign extension.

Coverity issue: 370608, 370610, 370612
Fixes: 873e8dad6f49 ("vhost: support packed ring in async datapath")

Signed-off-by: Cheng Jiang <7a6a77dd7576bfdf5dac8a9250f1050e5c53c3d0@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk